Particle size distribution profile of some Indian fly ash-a comparative study to assess their possible uses

Fly ash collected from three different thermal power plants in Eastern India were critically examined in respect to their particle size distribution. The objective of the investigation was to obtain proper distribution profiles of such ashes with the nature of combustors vis-à-vis their efficiency and to point out the possible areas of application/utilisation. For this purpose, particle size distribution profiles of the as received fly ash, the size fractionated ones as well as the magnetic and non-magnetic components, were determined. Distribution profiles reveal that fly ash obtained from Super Thermal Power Plants have better profiles than the fly ash obtained from captive power plants. It is observed that, in general, the finer fractions have a better profile in the sense that a considerable amount of the particles fall below 45 μm range; this is important in respect to utility in the construction industry. The magnetic particles are larger and rounder than the non-magnetic ones, and can probably be used for coal flotation. An important observation is that the fly ash collected from Stoker-fired thermal power plants possesses very poor distribution profile (AMD for as received fly ash ≥200 μm).